1. Field of the Invention
The present invention relates to an image processing apparatus, a control method therefor, and a computer-readable storage medium storing a program for implementing the control method, and in particular to a display control technique for use in displaying a variety of information as well as images on a display which the image processing apparatus has.
2. Description of the Related Art
In recent years, the resolution of images during video shooting by video cameras have been continuously increasing from Standard Definition (SD) to High Definition (HD) and further to 4K or Super High-Definition (SHD). It should be noted that 4K is a video format with a screen resolution of approximately 4000 horizontal pixels by 2000 vertical pixels, and examples thereof include a resolution of 4096×2160/24p defined by DCI (Digital Cinema Initiatives). In step with this trend, not only HD televisions but also 4K televisions have come along as ordinary televisions, and environments from shooting to viewing have been improving.
On the other hand, there are image pickup apparatuses whose main body is equipped with displays such as a panel monitor and a viewfinder, which display an image being taken, so that during actual shooting, a user can check the angle of view and the brightness of an image being taken. Also, there are known image pickup apparatuses which have a video output terminal for outputting an image being taken to a relatively large external monitor so that details of an image being taken such as image quality can be checked. In either arrangement, when an image being taken is to be displayed on each of the panel monitor, the viewfinder, and the external monitor, which are image output destinations, information for grasping various statuses during shooting (hereafter referred to as “shooting information”) when necessary needs to be displayed in a superimposed manner.
The panel monitor, the viewfinder, and the external monitor have different resolutions in many cases, and it is thus necessary to resize an image according to image output destinations. When decimation or interpolation is performed in such resizing, degradation of quality such as streaking or blurring of straight lines or the like with clear brightness and color difference which are used for characters that represent shooting information, or turning-off of display may be more likely to occur particularly in a taken image that does not have a fine gradation.
To prevent this problem, superimposition data for shooting information is created in advance with respect to image output destinations in accordance with resolutions thereof, and shooting information is displayed using the corresponding superimposition data in a manner being superimposed on an image being taken, which is to be displayed on the mage output destination, in many cases.
On the other hand, as a method to display shooting information superimposed on an image while maintaining quality in accordance with resolutions of image output destinations, there has been proposed a method that generates font information, which is suited to a plurality of resolutions, from one piece of font data (see Japanese Laid-Open Patent Publication (Kokai) No. 2007-243923). According to this method, from one piece of font data, thick-line font data is generated in a case where resizing is to be performed for a small screen, and font data with an optimum design is generated in a case where resizing is to be performed for a large screen.
However, according to the method that creates superimposition data for shooting information with respect to image output destinations and in accordance with resolutions of the image output destinations, the amount of data increases with an increase in the number of image output destinations and hence high-capacity ROM or RAM is required so as to hold superimposition data. Moreover, a problem of an increase in the load of a display signal generation process carried out by a control circuit of an apparatus main body so as to superimpose superimposition data on an image arises.
On the other hand, the technique described in Japanese Laid-Open Patent Publication (Kokai) No. 2007-243923 can reduce the storage capacity of ROM, RAM, or the like, which stores display fonts which are superimposition data.
Display fonts created using the method described in Japanese Laid-Open Patent Publication (Kokai) No. 2007-243923, however, are not completely suited to resolutions of image output destinations. For this reason, the quality of shooting information displayed when resizing is performed as a result is worse compared to the method that creates superimposition data in advance according to resolutions of image output destinations. Moreover, generation of data for displaying shooting information is required for each of image output destinations, and this process as well as a process to generate font data for respective resolutions from one piece of font data brings about an increase in processing loads on the control circuit of the apparatus main body.